磺甲基化腐植酸缩聚物的合成及性能应用

以腐植酸、甲醛、对氨基苯磺酸钠、尿素等为原料,依次经过磺甲基化、缩聚反应合成了两种具有不同侧链结构的腐植酸分散剂,磺甲基化腐植酸缩聚物(简称HBF)和磺甲基化腐植酸脲醛缩聚物(简称HBUF)。通过对比考察了两种分散剂对陕西彬长煤的水煤浆的成浆性能、浆体稳定性能以及两种分散剂在煤颗粒表面的吸附性能,结果表明,具有较长侧链的HBUF分散剂具有较好的分散降粘效果,其用量为0.45%时,彬长煤的最高制浆浓度达68%,两种分散剂在煤颗粒表面均呈现单分子层吸附特征,其中HBUF吸附量大,吸附平衡常数高。     

PAANH4-凹凸棒石粘土水悬浮液分散稳定性研究

研究了PAANH4 凹凸棒石粘土水悬浮液分散稳定性。结果表明 :固相质量分数不同的浆料 ,其最佳分散剂添加量均为 4 .5 %。固相质量分数的提高 ,浆料最低粘度值提高 ,分散剂有效用量范围变窄。对于给定PAANH4 添加量的浆料 ,其流变性随着pH的提高有明显的改善 ;pH值为 6 .5的悬浮液 ,经过高于 6 .5阶段的吸附 ,其流变性能均显著改善 ,而经过pH值为 8.5阶段的吸附的悬浮液粘度值最小。     

腐殖酸丙烯酰胺接枝共聚物的合成及性能研究

采用水溶液聚合方法,以过硫酸钾为引发剂,以腐植酸钾、丙烯酰胺为原料进行接枝共聚反应。考察了引发剂用量、单体配比、反应温度和反应时间等因素对水煤浆表观粘度的影响。确定了最佳聚合工艺条件为反应温度75℃、反应时间2.5h、引发剂用量5%、丙烯酰胺与腐殖酸质量比为0.8∶1。当分散剂用量为水煤浆总质量的3%时,水煤浆的表观粘度为790mPa.s。通过对水煤浆的粘度、稳定性研究,以及水煤浆的表观粘度的测定,得知该分散剂具有腐植酸系分散剂的特点,即分散性能佳,又改变了腐植酸系分散剂容易沉淀、成浆性能差的特点。     

羧基/磺酸基含量对聚羧酸盐水煤浆分散剂性能的影响

以甲基丙烯酸(MAA)、烯丙基磺酸钠(SAS)按一定比例合成了5种含有不同—COO~(-1)/—SO_3~(-1)比值的聚羧酸盐水煤浆分散剂PMAS系列。并通过红外光谱(FT-IR)、凝胶渗透色谱(GPC)进行了表征。并将其作用于彬长煤制浆,在用量0.4%(质量分数)时,水煤浆浆浓为65%时,考察了浆体的表观黏度与—COO~(-1)/—SO_3~(-1)比值的关系,在不同浓度下的zeta电位以及pH值对水煤浆应用的影响等。结果表明,当—COO~(-1)/—SO_3~(-1)比值为约3.238时,浆体的表观粘度最低,稳定性理想,此时浆体的zeta电位能达到-38mV,水煤浆粘度随着pH值的增大逐渐降低,当pH值大于10时水煤浆粘度趋于稳定。     

碱性水基氧化铝陶瓷料浆的流变学研究

采用流变的方法在RV－20型流变仪上研究了不同条件对碱性氧化铝悬浮体的流变性的影响，重点研究了固含量，分散剂加入量，球磨工艺对料浆流变性的影响，结果表明：分散剂的加入量对料浆的临界剪切速率具有显著的影响，随着球磨时间的延长，料浆的“剪切增厚”临界剪切速率增大。     

超声波强化庞庄煤制浆的试验研究

使用自制的新型萘油添加剂对庞庄煤制浆,考察了超声作用前后煤浆中煤粉粒度分布与添加剂在煤粒表面吸附能力的变化及其对水煤浆性能的影响。煤浆经超声作用后,浆体中细级煤粒的含量与煤粒对萘油添加剂的平衡吸附量都增加,煤浆稳定性显著提高。在超声发射强度为60W/cm2,频率为20kHz,萘油添加剂加入量为1%的条件下,超声辐照时间小于3min时煤浆粘度降低,辐照时间超过3min,煤浆粘度反而升高。当添加剂加入量为2%时,浆体粘度在试验超声作用时间内一直降低。     

UV固化水性超支化聚酯的制备研究

以季戊四醇为核、2,2-二羟甲基丙酸为臂单体合成第一代超支化聚酯;然后以第一代超支化聚酯为核,2,2-二羟甲基丙酸为臂单体合成第二代超支化聚酯,采用丙烯酰氯、顺丁烯二酸酐对第二代超支化聚酯进行改性,合成了UV固化水性超支化聚酯,并对其进行了红外光谱和差热分析,研究了丙烯酰氯、顺丁烯二酸酐用量对涂膜性能的影响。结果表明,当超支化聚酯、丙烯酰氯、顺丁烯二酸酐三者的物质的量之比为1∶6∶8时,水性超支化聚酯的稳定性和涂膜的耐水性较好。     

超支化聚醚胺杂化水凝胶的制备及其吸附行为研究

以1,8-对孟二胺为胺单体,与环氧封端的聚醚发生亲核加成/开环反应得到含双键的超支化聚醚胺,经双键与巯基的"点击化学"反应引入三甲氧基硅烷基团,通过甲氧基在纯水中水解交联得到超支化聚醚胺杂化水凝胶,采用红外光谱和扫描电镜对杂化水凝胶进行表征,并测得杂化水凝胶的平衡吸水率。以杂化水凝胶(Gel-3)为吸附剂对3种染料分子(甲基橙、中性红、丽春红S)进行吸附研究,考查了吸附时间和染料初始浓度对吸附量的影响。详细探讨了Gel-3对3种染料的吸附动力学模型和吸附等温线。结果表明:杂化水凝胶的饱和吸水率随着亲水性链段聚乙二醇二缩水甘油醚(PEO-DE)的增加而增加;饱和吸附量随着初始浓度的增加而增加;Gle-3对3种染料的吸附符合准二级动力学方程和Langmuir吸附等温线,是单分子层吸附过程。     

聚羧酸盐SAS/MAA/APEG的制备与性能分析

以烯丙基聚乙二醇(APEG),甲基丙烯酸(MAA),烯丙基磺酸钠(SAS)为单体,在引发剂过硫酸钾(K2S2O8)、阻聚剂对苯二酚作用下直接聚合得到一系列具不同侧链长度的三元聚醚聚羧酸盐分散剂。通过红外光谱、热重分析、差示扫描量热分析和凝胶渗透色谱等手段对聚合物的结构、热力学性能和相对分子质量及其分布进行了表征和分析。将其作用于彬长煤制浆,考察了浆体的表观黏度、流变性、Zeta电位、最大成浆浓度和稳定性,并测定和煤的接触角。结果表明,侧链长度为SAS/MAA/APEG1000(n=23)的聚羧酸盐分散剂在最佳用量为0.4%时,水煤浆最高制浆浓度可达到72%,Zeta电位由-12.6 mV变化到-53.1 mV,具有良好的润湿效果,对彬长煤具有更好的降粘、分散和稳定作用。     

梳形聚羧酸盐AMPS/MAA/MAAMPEG的制备与性能研究

以甲氧基聚乙二醇(MPEG,氧乙烯单元数为11,23)和甲基丙烯酸(MAA)为原料制得甲氧基聚乙二醇甲基丙烯酸酯化单体(MAAMPEG);再以该酯化单体、甲基丙烯酸和2-丙烯酰胺-2-甲基丙磺酸(AMPS)为原料,制得具有不同长度侧链的梳形聚羧酸盐(PC)分散剂AMPS/MAA/MAAMPEG(AMAPEG)。利用核磁共振氢谱(~1 H-NMR)、红外光谱仪(FT-IR)、凝胶渗透色谱仪(GPC)对分散剂分子的结构、分子质量及分布进行了表征;并将其和工业分散剂萘磺酸盐(NSF)用于彬长煤制水煤浆,结果表明,所得目标聚合物的Mw为2×10~4~3×10~4,分子量分散系数D在约为1.3,煤质量浓度为65%时,最佳用量为0.4%,浆体粘度约为447mPa·s,zeta电位达到-56mV,比萘磺酸盐具有良好的润湿效果,更好的降粘分散和稳定作用。     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.     

空压机轴承箱蜗壳温度探头油封改造

由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。     

Characteristics of mechanical properties of materials in studies of conditions of attainment of marginal states

It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle.     

Determination of parameters of microstructural inhomogeneity of deformation of metals by the method of modeling

The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.     

水三相点复现的不确定度评定

水三相点是开尔文热力学温度的唯一基准点，也是ITS-90国际温标重要的定义固定点。因此，水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来，中国计量科学研究院研制出一系列高质量的水三相点容器，加强了水三相点的研究，为不确定度的分析提供了更为可靠的实验依据。同时，不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此，根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明，其扩展不确定度为0．16mK(k=2．69，P=0．99)。